This invention relates generally to the art of electronic instrumentation and, more particularly, to an electronic musical instrument wherein oscillator sets and multiple voices are each assigned a unique PCM data channel for sound production.
Most synthesizers, samplers, or drum machines available on the market today provide the user with a maximum of approximately 32 oscillators or voices. Currently, music manufacturers typically assign all PCM data in internal memory, which is being "played" by a keyboard, to one set of oscillators. For example, PCM data or "samples" from several musical instruments are assigned to one group of oscillators, usually having a maximum of 32 oscillators in that one group.
The standard design creates a problem for keyboard players since when all oscillators (voices) are triggered at one moment in time, no more notes will be played from the device. In other words, for a 32 oscillator device, once 32 keys are depressed simultaneously on the keyboard, no more will play. Also, if sounds are layered on top of one another, such as a piano chord on top of an organ chord, the maximum number of notes or voices playable declines with each note played. For example, a three note piano chord layered on top of a three note organ chord uses six oscillators or voices, leaving only 26 playable notes left from the original 32. This decline of available voices is the cause of "note drop out" that occurs when keyboards are connected via a standardized musical instrument digital interface (MIDI) and the "Note On" number exceeds the number of voices available in the musical device.